Low-voltage circuit breaker

ABSTRACT

A low-voltage circuit breaker includes a first contact arrangement, for connecting a fixed contact to a first busbar and a second contact arrangement, for connecting a counter contact, arranged on a contact lever, to a second busbar. A low-voltage circuit breaker is produced, which may be converted with minimal material complexity and little effort from a fixed switch into a modular switch, whereby the busbars of a low-voltage circuit breaker include moulded features such that the low-voltage circuit breaker may be embodied as both a fixed breaker and a modular breaker.

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/DE2003/003926which has anInternational filing date of Nov. 25, 2003, which designated the UnitedStates of America and which claims priority on German Patent Applicationnumber DE 102 60 371.5 filed Dec. 13, 2002, the entire contents of whichare hereby incorporated herein by reference.

FIELD

The invention generally relates to a low-voltage power circuit breaker.For example, it may relate to one having a first contact arrangement forthe purpose of connecting a stationary contact to a first busbar andhaving a second contact arrangement for the purpose of connecting anopposing contact, which is arranged on a contact lever, to a secondbusbar.

BACKGROUND

Low-voltage power circuit breakers have contact arrangements in order tomake it possible to rapidly connect or isolate the circuit breaker to orfrom current-carrying rails. This is desirable, inter alia, for thepurpose of removing or carrying out maintenance on the low-voltage powercircuit breakers. Low-voltage power circuit breakers are provided withdifferent sizes for different rated currents. The aim here is to keepthe physical dimensions of a low-voltage power circuit breaker as low aspossible.

Low-voltage power circuit breakers of the type mentioned may be in theform of permanently installed circuit breakers on the one hand orwithdrawable circuit breakers on the other hand. In the case ofwithdrawable circuit breakers, the power circuit breaker is moved andlocked in a withdrawable part rack which is provided for this purpose.This makes it possible to connect or isolate the power circuit breakerto or from the busbars more quickly and more easily than in the case ofpermanently installed circuit breakers. It is therefore desirable to beable to convert permanently installed circuit breakers to withdrawablecircuit breakers with as little complexity in terms of materials andwork as possible.

SUMMARY

It is an object of an embodiment of the present invention to specify alow-voltage power circuit breaker which can be converted from apermanently installed circuit breaker to a withdrawable circuit breakerwith a reduced or even minimum amount of complexity in terms ofmaterials and work.

One particular advantage of an embodiment of the present invention isthe fact that the already provided busbars of a permanently installedcircuit breaker can be reused in a very simple manner in the conversionto a withdrawable circuit breaker. For this purpose, the busbars of alow-voltage power circuit breaker have design features such that thelow-voltage power circuit breaker can be in the form of both apermanently installed circuit breaker and a withdrawable circuitbreaker.

In an example embodiment, the busbars have at least one contact regionby which the busbars can be arranged permanently on a withdrawable partrack of a low-voltage power circuit breaker. Furthermore, the busbarshave at least one accommodating region for a retaining device(s), bywhich the busbars can be arranged permanently on a withdrawable partrack of a low-voltage power circuit breaker.

In an example embodiment, the accommodating region for retainingdevice(s) and the contact region are designed such that the busbars canbe arranged permanently, but reversibly, on a withdrawable part rack ofa low-voltage power circuit breaker.

The abovementioned embodiment of the busbars may make it possible, forexample, for them to be arranged directly on the permanently installedcircuit breaker for use in a permanently installed circuit breaker.Further, it is also possible for these busbars to be arrangedpermanently on the withdrawable part rack of a withdrawable circuitbreaker when the permanently installed circuit breaker is converted to awithdrawable circuit breaker once said busbars have been removed fromthe permanently installed circuit breaker, with the result that theconversion of a permanently installed circuit breaker to a withdrawablecircuit breaker entails a minimum amount of complexity in terms ofmaterials since only one additional withdrawable part rack is requiredfor this conversion.

Owing to the contact region provided, the busbars can be arrangeddirectly on the withdrawable part rack. In this case, the surfaces ofthe contact region should end evenly with the surface of thewithdrawable part rack with which contact is to be made. As a result ofthe fact that the busbars have an accommodating region for retainingdevice(s), it is possible for them to be permanently provided with aretaining means and, as a result, to be permanently locked on thewithdrawable part rack of a power circuit breaker.

In a particular example embodiment, both the first and the second busbarhave identical dimensions. This advantageously makes it possible for thesame contact arrangements, which are preferably in the form of isolatingcontact arrangements, to be used both for the first busbar and for thesecond busbar.

In accordance with a further example embodiment, the busbars can bearranged on the withdrawable part rack such that the withdrawable partrack has the same installation depth as the busbars in a permanentlyinstalled circuit breaker. This ensures that the busbars need bearranged permanently on the withdrawable circuit breaker merely usingretaining device(s) in the regions of said busbars which are providedfor this purpose in order to convert the permanently installed circuitbreaker to a withdrawable circuit breaker. As a result of the fact thatthe busbars arranged on a withdrawable part rack have the sameinstallation depth as the busbars in the case of a permanently installedcircuit breaker, no further adaptation or conversion work is required.

In an example embodiment, the busbars are in the form of plates orblades.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below with reference toexample embodiments which are at least partially illustrated in thefigures, in which:

FIG. 1 shows a low-voltage power circuit breaker according to anembodiment of the invention which is in the form of a permanentlyinstalled circuit breaker having closed contacts;

FIG. 2 shows a low-voltage power circuit breaker according to anembodiment of the invention which is in the form of a permanentlyinstalled circuit breaker having open contacts;

FIG. 3 shows a low-voltage power circuit breaker according to anembodiment of the invention having a corresponding withdrawable partrack, and

FIG. 4 shows a low-voltage power circuit breaker according to anembodiment of the invention which is in the form of a withdrawablecircuit breaker.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

As can be seen in FIG. 1, a low-voltage power circuit breaker 10 has afirst contact arrangement 24 which produces a connection between a firststationary contact 18, which is arranged on a connection rail 17, and afirst busbar 22. Furthermore, the power circuit breaker 10 has a secondcontact arrangement 34 for the purpose of connecting a second busbar 30to an opposing contact 16 which is arranged on a contact lever 14. Thelow-voltage power circuit breaker 10 is in the form of a permanentlyinstalled circuit breaker in FIG. 1 by the two busbars 22 and 30, whichserve the purpose of producing a connection to system-side busbars whichare not further illustrated, being fixed to the outside of the rear wallof the power circuit breaker 10. First retaining means 12, which passthrough first accommodating regions 20 of the busbars, are used for thisfixing. The connection to the system-side busbars takes place usingsecond retaining device(s) (not illustrated) which pass through secondaccommodating regions 13 of the busbars 22 and 30.

In order to reduce the variety of circuit breaker parts required andthus to save on production costs, the connection rail 17 and the busbars22 and 30 are of identical design, the accommodating region 13 of theconnection rail 17 serving the purpose of accommodating a fourthretaining means 15. The fourth retaining device(s) 15 serves the purposeof fixing an arcing horn 19 on the connection rail 17.

The first busbar 22 and the second busbar 30, which according to theinvention have the accommodating region 20 for retaining device(s) and acontact region 38 for the purpose of arranging the busbars 22, 30 on awithdrawable part rack 11 of the power circuit breaker 10, make contactwith the power circuit breaker 10 with their side which faces the powercircuit breaker 10. The accommodating region 20 is in the form of athrough-hole. The contact region 38 is located on that side of thebusbars 22, 30 which is remote from the power circuit breaker 10.

The contact region 38 makes it possible to remove the busbars 22, 30according to an example embodiment of the invention of a permanentlyinstalled circuit breaker, as illustrated in FIG. 1 and FIG. 2, from thepermanently installed circuit breaker and to arrange them on awithdrawable part rack 11 of a power circuit breaker 10, as isillustrated in FIG. 3. Furthermore, the busbars 22, 30 which arearranged in this manner on the withdrawable part rack 11 can bepermanently locked by means of third retaining device(s) 35. Theretaining device(s) bring about a permanent, force-fitting connectionbetween the busbars 22, 30 and the withdrawable part rack 11 (as isillustrated in FIG. 4) by way of the accommodating regions 20 forretaining device(s).

As has been described above, conversion of the power circuit breakeraccording to an embodiment of the invention from a permanently installedpower circuit breaker to a withdrawable power circuit breaker can berealized in a particularly advantageous manner. The busbars 22, 30,which are locked and arranged on the withdrawable part rack, of thepower circuit breaker which is in the form of a withdrawable powercircuit breaker advantageously have the same installation depth X as thebusbars of a power circuit breaker which is in the form of a permanentlyinstalled circuit breaker, in its operating position.

For this purpose, the busbars 22 and 30 are arranged on the inside ofthe withdrawable part rack which is associated with the withdrawablepower circuit breaker such that they make contact with the power circuitbreaker with their side which faces the power circuit breaker when thewithdrawable power circuit breaker is pushed in, as is also the casewith the power circuit breaker in FIGS. 1 and 2 which is designed forpermanent installation.

The position of the busbars 22 and 30 with respect to the contactarrangements 24 and 34 and with respect to the system-side busbars (notillustrated) is therefore the same in the case of the power circuitbreaker in FIGS. 1 and 2, which is in the form of a permanentlyinstalled power circuit breaker, as in the case of the power circuitbreaker in FIGS. 3 and 4, which is in the form of a withdrawable powercircuit breaker.

Example embodiments being thus described, it will be obvious that thesame may be varied in many ways. Such variations are not to be regardedas a departure from the spirit and scope of the present invention, andall such modifications as would be obvious to one skilled in the art areintended to be included within the scope of the following claims.

1. A system comprising: a first busbar; a second busbar; and alow-voltage power circuit breaker including a first contact arrangementfor connecting a stationary contact to the first busbar, and a secondcontact arrangement for connecting an opposing contact, arranged on acontact lever, to the second busbar, each of the first and secondbusbars including at least one contact region by which the busbars arepermanently arrangeable on a withdrawable part rack of the low-voltagepower circuit breaker, each of the first and second busbars having aside which faces the low-voltage power circuit breaker, by which thebusbars are permanently arrangeable on the outside of the low-voltagepower circuit breaker, and each of the first and second busbarsincluding at least one accommodating region for at least one retainingdevice by which the busbars are permanently lockable on the withdrawablepart rack of the low-voltage power circuit breaker so as to form thelow-voltage power circuit breaker as a withdrawable circuit breaker oron the outside of the low-voltage power circuit breaker so as to formthe low-voltage power circuit breaker as a permanently installed circuitbreaker, wherein the busbars are arrangeable on the withdrawable partrack when the low-voltage power circuit breaker is a withdrawablecircuit breaker such that they have a same installation depth as thebusbars when the low-voltage power circuit breaker is a permanentlyinstalled circuit breaker.
 2. The system as claimed in claim 1, whereinthe busbars are in a form of at least one of plates and blades.
 3. Thesystem as claimed in claim 1, wherein the accommodating region for theat least one retaining device and the side which faces the low-voltagepower circuit breaker are designed such that the busbars are permanentlyarrangeable and lockable, reversibly, on the outside of the low-voltagepower circuit breaker.
 4. The system as claimed in claim 3, wherein thefirst busbar and the second busbar have identical dimensions.
 5. Thesystem as claimed in claim 3, wherein the busbars are arrangeable on thewithdrawable part rack when the low-voltage power circuit breaker is awithdrawable circuit breaker such that they have the same installationdepth as the busbars when the low-voltage power circuit breaker is apermanently installed circuit breaker.
 6. The system as claimed in claim3, wherein the busbars are in a form of at least one of plates andblades.
 7. The system as claimed in claim 3, wherein the accommodatingregion for the at least one retaining device and the contact region isdesigned such that the busbars are permanently arrangeable and lockable,reversibly, on the withdrawable part rack of the low-voltage powercircuit breaker.
 8. The system as claimed in claim 7, wherein the firstbusbar and the second busbar have identical dimensions.
 9. The system asclaimed in claim 1, wherein the accommodating region for the at leastone retaining device and the contact region are designed such that thebusbars are permanently arrangeable and lockable, reversibly, on thewithdrawable part rack of the low-voltage power circuit breaker.
 10. Thesystem as claimed in claim 9, wherein the first busbar and the secondbusbar have identical dimensions.
 11. The system as claimed in claim 9,wherein the busbars are in a form of at least one of plates and blades.12. The system as claimed in claim 1, wherein the first busbar and thesecond busbar have identical dimensions.
 13. The system as claimed inclaim 12, wherein the busbars are in a form of at least one of platesand blades.